Antiarrhythmic drugs, including procainamide, may increase the risk of death. Tell your doctor if you have had a heart attack within the past two years. Procainamide should be used only to treat life-threatening arrhythmias (irregular heartbeats).

Procainamide may cause a decrease in the number of cells in your bone marrow. Procainamide may also cause symptoms of lupus.

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to procainamide.

If you experience any of the following symptoms, call your doctor immediately: fever, chills, sore throat, bruising, bleeding, muscle aches or weakness, stomach or chest pain, skin rash, or blisters on the cheek, tongue and lips.

Talk to your doctor about the risks of taking procainamide.

Procainamide is used to treat abnormal heart rhythms. It works by making your heart more resistant to abnormal activity.

Procainamide comes as a capsule and tablet to take by mouth. Immediate-acting procainamide usually is taken every 3 or 4 hours. The long-acting product is usually taken every 6 or 12 hours. Do not cut, crush, or chew extended-release (long-acting) tablets; swallow them whole. You may see a waxy core in your stool if you are taking the extended-release product; this is normal.

Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take procainamide exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Procainamide helps control your condition but will not cure it. Continue to take procainamide even if you feel well. Do not stop taking procainamide without talking to your doctor.

This medication should not be prescribed for other uses; ask your doctor or pharmacist for more information.

Before taking procainamide,

• Tell your doctor and pharmacist if you are allergic to procainamide, anesthetics, aspirin, or any other drugs.
• Tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially digoxin (Lanoxin) or drugs for high blood pressure, and vitamins.
• In addition to the condition listed in the IMPORTANT WARNING section, tell your doctor if you have or have ever had lupus, heart disease, high blood pressure, kidney or liver disease, or myasthenia gravis.
• Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking procainamide, call your doctor.
• If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking procainamide.
• You should know that this drug may make you dizzy. Do not drive a car or operate machinery until you know how this drug affects you.
• Remember that alcohol can add to the dizziness caused by this drug.
• Talk to your doctor about the use of cigarettes and caffeine-containing beverages. These products may increase the irritability of your heart and interfere with the action of procainamide.

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

Procainamide may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• Dizziness or lightheadedness
• Loss of appetite
• Upset stomach
• Vomiting
• Bitter taste

If you experience the following symptom or any of those listed in the IMPORTANT WARNING section, call your doctor immediately:

• Irregular heartbeat

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.

Keep all appointments with your doctor and the laboratory. Your doctor will need to determine your response to procainamide.

Take procainamide at the same time each day in regularly spaced intervals. Changing the time of your doses prevents procainamide from working effectively.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.